If $x \bigtriangledown y = x(y-3)$ and $x \boxdot y = x^{2}+3y^{2}$, find $(-3 \boxdot 1) \bigtriangledown 2$.
Explanation: First, find $-3 \boxdot 1$ $ -3 \boxdot 1 = (-3)^{2}+3(1^{2})$ $ \hphantom{-3 \boxdot 1} = 12$ Now, find $12 \bigtriangledown 2$ $ 12 \bigtriangledown 2 = 12(2-3)$ $ \hphantom{12 \bigtriangledown 2} = -12$.